You can purchase an additional/several social profile/s for your Iconosquare account here.
On the STARTER plan, which gives you 1 social profile for $9, an additional profile costs $9/per month (please note, the STARTER plan is not available for new subscribers).
On the PRO monthly plan, which gives you 3 social profiles for $39, an additional profile costs $19/per month.
For the ADVANCED plan, which gives you 5 social profiles for $79, an additional profile is $29/per month.
For more slots, you can either upgrade your plan or subscribe to additional profile(s).
Also known as "What is the price of an additional slot for my social profiles?"